A package for a micro-electro-mechanical system (MEMS) spatial light modulator (SLM) integrated circuit (IC) is required to perform the functions of (1) furnishing an electrical connection between the integrated circuit (IC) and the system using the integrated circuit (IC), where the electrical connection must provide sufficient electrical signal integrity, (2) furnishing a thermal connection between the integrated circuit (IC) and the system using the integrated circuit (IC), where the thermal connection must provide a sufficiently low thermal resistance, and (3) furnishing opto-mechanical alignment between the integrated circuit (IC) and the system using the integrated circuit (IC), where the mechanical alignment features and/or mechanism must provide sufficient alignment tolerance. The combination of the second and third functions stated above suggests that the package must provide sufficient structural integrity to endure the mechanical loads associated with those functions. Additionally, end-products that utilize such micro-electro-mechanical system (MEMS) spatial light modulator (SLM) integrated circuit (IC) devices typically also require that the packaged device consume the smallest possible installed footprint.
Current, conventional state-of-the-art design approaches are, (A) composite construction, and (B) principle-member construction. These two design approaches represent a trade-off between structural integrity and installed footprint size.
Composite construction strives to achieve sufficient structural integrity as a consequence of assembling a number of piece-parts into a final package assembly. In this case, no single piece-part by itself provides adequate structural integrity. Only the combination of the individual piece-parts can hope to achieve sufficient structural integrity. Such a composite construction carrier may have a relatively small package footprint owing to the fact that features (electrical, mechanical, and thermal) may be stacked on top of each other. However, optimization of the overall design of such a composite construction carrier disadvantageously is complicated by the fact that each of the plurality of piece-parts has an effect on the structural integrity of such a composite construction carrier, which, in turn, places additional restrictions on the design and/or composition of each piece-part. For example, the coefficient of thermal expansion (CTE) of each piece-part must be matched, since mis-matches in the coefficient of thermal expansion (CTE) have the potential of negatively impacting the structural integrity of the overall design.
Principle-member construction strives to achieve sufficient structural integrity as a consequence of providing a single piece-part of the overall package to impart substantially all of the structural integrity. Such a principle-member construction carrier may have alignment tolerances minimized because most, if not all, of the tolerances are contained in a single piece-part. However, such a principle-member construction carrier disadvantageously has a much larger package footprint owing to the fact that features, principally electrical and mechanical, are located in essentially the same plane and must be spread out to eliminate physical interference.